Effect of Hydraulic Loading Rate on the Performance of Night-soil Wastewater Land Treatment Technology

A novel artificial soil column system(ASC) was constructed and applied to the night-soil wastewater treatment.The soil column was composed of soil,sand,macromolecule organic hydrophilic materials,etc.The results showed that ASC had a high stable removal rate on organic matfer,nitrogen,phosphorus etc.in night-soil wastewater,the average removal rate of CODCr,BOD5,TN,TP were 91.7 %,96.2 %,95.6 %,96.0 % and 99.8 %,respectively.The study on hydraulic loading rate showed that shock loading had little effect on the removal rate of CODCr,BOD5,TN,TP,and so on,but it had great effect on saturated infiltration rate of the infiltration system.When hydraulic loading rate increased to 50 cm/d,saturated infiltration rate was decreased to 2/3 of its initial date.In order to maintain the long-term stability of ASC system,hydraulic loading rate should be kept under 31.25 cm/d.